The present disclosure relates generally to instrumentation used in a medical procedure, and more particularly, relates to a guide or targeting apparatus used in the reduction of a hip fracture.
A procedure regularly performed by orthopaedic surgeons is the reduction of a hip fracture caused by trauma. The site of this type of fracture typically exists at the proximal portion of the femur below the femoral head. In order to reduce a fracture of this type, an elongated lag screw is threadingly advanced into the shaft, neck, and head of the femur. In certain procedures, the proximal end of the lag screw is secured to a bone plate. Cortical screws are used to secure the bone plate to the femur distal to the fracture site. Tightening of the lag screw compresses the bone fragments together and facilitates healing of the femur. Many devices have been designed for this type of reduction including the devices disclosed in U.S. Pat. Nos. 4,438,762, 3,554,193, and 2,526,959, the disclosures of which are incorporated herein by reference in their entirety.
In other procedures, a stabilizing element, such as an intramedullary rod or nail, may be advanced into the medullary canal of the femoral shaft. The intramedullary rod includes a transverse aperture that is oriented at an appropriate angle to support and anchor the proximal portion of the lag screw. In some cases, a compression screw is also introduced into the fractured bone to reduce the fracture. The compression screw also extends through the intramedullary rod adjacent the lag screw. An example of a device of this type is disclosed in U.S. Pat. No. 5,562,666 to Brumfield, the disclosure of which is incorporated herein by reference.
In many surgical procedures, various jigs or similar apparatuses are used to guide the creation of targeting holes in the bone. More specifically, jigs or targeting devices may be used to guide drilling for and insertion of fracture fixation screws, such as the lag and compression screws described above. Proper targeting is more problematic for fixation systems utilizing intramedullary rods/nails, rather than external plates because the transverse openings in the intramedullary implant are contained within the bone and are not directly visible. While various imaging devices may be used to guide a drilling operation or screw insertion, the images are planar and do not easily provide three-dimensional targeting or alignment. Thus, various jigs or targeting devices have been developed to facilitate various steps in the fracture reduction and fixation process.
It is a goal of designers of medical instrumentation to design apparatus used in hip fracture reduction procedures that facilitate implantation of the fracture fixation components in as minimally invasive manner as possible. While many targeting jigs meet this goal, these prior apparatuses are often complex and require assembly of multiple components. Non-modular devices are known that eliminate the plurality of components found in prior modular systems, but at the cost of non-universality—i.e., non-modular devices are designed for only certain specific fixation arrangements, such as a specific angular orientation of a lag screw relative to an intramedullary rod/nail.
What is needed therefore is an assembly used in hip fracture reduction procedures that facilitates implantation of a fracture fixation apparatus and simplifies the procedure. The system should be modular and universal without the need for the surgeon to assemble several components before the alignment and targeting steps can be commenced. There is also a need for such an assembly that minimizes or eliminates potential alignment errors that may occur during the procedure.